1. Field of the Invention
The present invention relates to compositions containing azo dye compounds which exhibit antiviral activity and methods for using the same. The azo dye compounds have the ability of inhibiting the binding of HIV rgp120 to CD4 cells on peripheral blood lymphocytes.
2. Description of Related Art
A variety of compounds have been shown to be able to block the binding of HIV to its cellular receptor, CD4. These include soluble CD4 (Smith, D. H. et al, "Blocking of HIV-1 infectivity by a soluble, secreted form of CD4 antigen," Science 238 1704-1707 (1987), synthetic fragments of CD4 (Lifson et al, "Synthetic CD4 peptide derivatives that inhibit HIV infection and cytopathicity," Science 241 712-716 (1988)). Other anti-HIV compounds include dextran sulfate (Ito et al, "Inhibitory effect of dextran sulfate and heparin on the replication of human immunodeficiency virus (HIV) in vitro," Antivir. Res. 7 361-367 (1987)), aurintricarboxylic acid (ATA), Evans Blue (EB) (Balzarini et al, "Aurintricarboxylic acid and Evans Blue represent two different classes of anionic compounds which selectively inhibit the cytopathogenicity of human T-cell lymphotropic virus type III/lymphadenopathy-associated virus," Biochem. Biophys. Res. Commun. 136 64-71 (1986a)), and Direct Yellow 50 (Balzarini et al, "Comparative inhibitory effects of suramin and other selected compounds on the infectivity and replication of human T-cell lymphotropic virus (HTLV-III)/lymphadenopathy-associated virus (LAY)," Int. J. Cancer 37 451-457 (1986b)). It has also previously been shown that ATA and EB act by binding to CD4 and blocking the binding of HIV rgp120 (Weaver et al, "Polyionic compounds selectively alter availability of CD4 receptors for HIV coat protein rgp120," AIDS Res. Human Retrovir. 6 1125-1130 (1990)).
Research has also been conducted concerning compounds with potential antiherpes activity, such as the dye Trypan blue (Alarcon et al, "Screening for new compounds with antiherpes activity," Antiviral Research, 4 (1984), pp. 231-243; and Thorne et al, "Inactivation of Measles and Herpes Simplex Viruses by Trypan Blue," J. gen. Viral. (1983), 64, pp. 1365-1368), as well as Indigocarnine and Paraorange (Westin et al, "Aromatic Sulfonic Acids as Inhibitors: Structure-Activity Study using Rhino, Adeno 3, Herpes Simplex, and Influenza Viruses," J. of Med. Chem., 1971, Vol. 14, No. 7, pp. 596-600). The dye Congo Red and derivatives thereof have been investigated for potential anti-AIDS activity (Mohan et al, "Potential Anti-AIDS Agents. Synthesis and Antiviral Activity of Naphthalenesulfonic Acid Derivatives against HIV-1 and HIV-2," J. Med. Chem., 1991, 34, pp. 212-217). Also a number of azo dyes were demonstrated to exhibit protective properties in mice infected by equine encephalomyelitis virus (Hurst et al, Brit. J. Pharmacol., 7, p. 455 (1952)).
In view of the above, it remains desirable to discover additional antiviral agents which are effective against the HIV virus.